The present invention relates to a magnetic circuit of a core-type electromagnet, inclusive of electric motors, having coils wound around ferromagnetic substances or of a coreless electromagnet having only coils wound, and more particularly to an electric circuit and a magnetic circuit constructed with two or more electromagnet coils wherein one coil is wound clockwise (S direction) and the other coil is wound counterclockwise (Z direction) and for providing a one-direction direct-current series control method of using a phenomenon that magnetic polarities are changed according to winding directions as electric currents flow with controls of a semiconductor switching device or a superconductive switching device mounted in front of the coils wound in the respective directions and a method of inducing alternating magnetic flux.
An alternating magnetic flux induction method which has been used so far is a method of generating an alternating electromotive force in a sinusoidal waveform due to changes of flux linkage of an induced magnetic flux in an armature coil wherein the magnetic flux of a field system is alternately induced in the armature by rotating the field system mounted on a shaft due to mechanical power and the mechanical power is obtained by attractive and repulsive forces generated through alternate applications of voltages to both ends of coils wound in an electric motor or other magnetic circuit.
The voltage or the voltage-applying method obtained as above is referred to as alternate current (AC). A concrete description added to the above will be as follows by using a view of FIG. 1 for showing a circuit of a conventional transformer.
An alternating switching method is repeated wherein, in coils 2 and 3 wound around a core 1 of a ferromagnetic substance, a direct current (DC) voltage is applied to an input terminal 4 for a certain period of time in an xe2x80x9cAxe2x80x9d direction and then cut off, and just after the cutoff, the DC voltage is applied to an opposite input terminal 5 in a xe2x80x9cBxe2x80x9d direction. Therefore, an alternating electromotive force is generated from output terminals 6 and 7.
The voltage applications through the alternating switching method require a high voltage application to obtain a rotation force of a high torque since reactance, that is, a functional resistance (alternate current resistance), is generated due to collisions with currents flowing against a current flow direction in addition to a coil material resistance to interrupt electric current applications in a proportion of a frequency magnitude.
In a theoretical description, the impedance is divided into a material resistance R and a reactance X largely changing according to frequencies, and the reactance is divided into the inductive reactance and the capacitive reactance. Impedance Z may be expressed as a following formula when a material resistance R, inductance L, capacitance C are connected in series:             Z      =                        R          +          jX                =                              R            +                          j              ⁡                              (                                                      X                    L                                    -                                      X                    C                                                  )                                              =                      R            +                          j              ⁡                              (                                  wL                  -                                      1                    wC                                                  )                                                          ,    and              "LeftBracketingBar"      Z      "RightBracketingBar"        =                                        R            2                    +                      X            2                              =                                                  R              2                        +                                          (                                  wL                  -                                      1                    wC                                                  )                            2                                      ⁡                  [          ohm          ]                    
In the above formula, if alternating magnetic flux may be induced without frequency changes, the reactance term jX is cancelled out, so there exists only the material resistance R.
However, a push-pull inverter showing in FIG. 2 as a conventional voltage-applying method can obtain an alternating electromagnetic force from the output terminal 3 by applying a DC voltage, but has difficulties in real-time switching controls of both terminals since currents flow into a coil connected to a left-side switch and a coil connected to a right-side switch by switches about a common ground coil to generate the alternating electromagnetic force, deteriorates energy efficiency since currents are cut off due to current collisions when both switches all turn on as well as a phase difference of voltage and current is generated due to a dead time, and generates a reactance of interrupting current flows due to a current flow inertia when the both switches mounted on both sides are abruptly turned on and off to obtain an alternating electromotive force.
A description is made in detail as follows through a view shown in FIG. 2.
As shown in FIG. 2a, if an S1 switch 24 turns on in the state that an S2 switch 25 turns off, a circuit is formed in which the positive voltage of a voltage source 23 is applied in a xe2x80x9cCxe2x80x9d direction from a common ground 26 to part of a coil 21 connected to the S1 switch, and to the negative voltage of the voltage source 23 along the S1 switch 24.
At this time, a current waveform 27 shown in FIG. 2b appears across an output coil 3, and, in reverse, if the S1 switch 24 turns off and the S2 switch 25 turns on, a circuit is formed in which the positive voltage of the DC voltage source 23 is applied from the common ground 26 to the part of the coil 22 connected to the S2 switch, and to the negative voltage of the voltage source 23 along the S2 switch 25, so a current waveform shown in FIG. 2b appears across the output coil 3.
When the above is repeated, an alternating electromotive force is generated across the output coil 3 by a mutual induction. When a description is made with a digital logic formula, the push-pull inverter may be interpreted as a combinational logic-type switch circuit of the Exclusive-OR(XOR) type.
However, such switching power input method, in case that it is applied to an electromagnet or a transformer using an iron core, a mutual induction appears to be distorted due to an instant saturation of a magnetic substance as well as electric currents are not conducted owing to current collision when all the switches turn on due to imbalance appearing between peak values of two switching currents caused by a switching time difference of the switches 24 and 25, and energy consumption increases due to a leakage inductance of a magnetic substance caused by the mutual induction and a hysteresis loss appearing upon interchanging N and S poles.
Particularly, since the method can be realized only a control method of a parallel structure, much more currents are required than a control method of a series structure upon applying currents at respective phases, an amount of electric power consumption increases a lot as an amount of heat release increases in proportion to the current amounts, and the heat becomes a cause of function deterioration.
Further, a method of driving an inverter of a two-phase hybrid electric motor of a two-power source type as shown in FIG. 3 has an object of rapidly increasing currents by applying a voltage over a rating voltage to the electric motor the instant inputs to the armature change due to the switch-on and switch-off of a switching transistor for rapid clockwise (CW) and counterclockwise (CCW) conversions.
That is, in a state that a voltage of 24 V is applied from a power source 31, it is structured that clockwise (CW) rotations are caused by turning on a transistor (TR1) 33-1 (when a transistor (TR2) 33-2 is turned off) with a transistor (TR3) 35-1 and a transistor (TR4) 35-2 alternately switching, and, in reverse, counterclockwise (CCW) rotations are caused by turning off the transistor (TR1) 33-1 in case that a transistor (TR5) 35-3 and a transistor (TR6) 35-4 are alternately switching.
The characteristics of this circuit increase response capability by rapidly increasing currents with support of 6.3 V of a power source 32 upon clockwise and counterclockwise conversions.
However, the driving circuit has a problem in that a high voltage is applied again as to a phase having been already operating with a low voltage, and can not maximize current efficiency since the circuit operates in a driving control method between phases based on a parallel-structured voltage input type.
In the meantime, FIG. 4a and FIG. 4b are views for showing an inverter circuit of a three-phase 180-degree conducting type electric motor and for explaining a method of obtaining a rotational magnetic field from sequential controls.
In FIG. 4a, if an S1 switch 42-1, an S5 switch 42-3, and an S4 switch 42-5 turn on in order to obtain a rotational magnetic field by switching a power source 41 as shown in a time sequence chart of FIG. 4b, a half of a voltage is applied along a V-phase coil 43-1 connected with VA node 45 and the rest of the voltage, that is, the remaining half of the voltage, is applied along a W-phase coil 43-3 connected with a VC node 47.
The voltages are combined at a neutral point 44 commonly grounded to flow to a negative terminal along an S4 switch 42-5 through a VB node 46 connected with a U-phase coil 43-2, so that an initial rotational magnetic field is generated.
Further, if the S5 switch 42-3 is turned off by a gate drive circuit not shown based on a next switching sequence (electrical angles from 60 degrees to 120 degrees) and the S1 switch 42-1, an S4 switch 42-5, and an S6 switch 42-6 are turned on, the voltage from the power source 41 is divided at the neutral point 44 commonly connected through the V-phase coil 43-1 connected with the VA node along the S1 switch 42-1, so an half of the voltage from the power source 41 is applied to the S4 switch 42-5 along the VB node 46 connected with an U-phase coil 43-2 to reach the negative terminal of the power source, and the remaining half of the voltage reaches an S6 switch 42-6 along the VC node 47 connected with the W-phase coil 43-3 and then returns to the negative terminal of the power source, to thereby cause a second-stage rotational magnetic field.
The switching is repeated according to the sequence order shown in FIG. 4b, so that a rotational power is obtained.
However, the driving method causes collisions between the voltages while changing the flows of the voltages as the half of the voltage passes the W-phase coil 43-3 connected via the S5 switch 42-3 already turned on and the VC node 47 and the neutral point 44 commonly connected to the respective phases in order to obtain a first stage (electrical angles between 0 degree to 60 degrees in the time sequence chart) rotational magnetic field and the S6 switch 42-6 is turned on while the S5 switch 42-3 is turned off, abruptly, in order to obtain a voltage returning to the negative terminal along the S4 switch 42-5 via the VB node connected with the U-phase coil 43-2 and the second-stage (electrical angles between 60 degrees to 120 degrees in the time sequence chart).
That is, if the S5 switch (42-3) is turn off and the S6 switch 42-6 is turned on, the voltage reaches the neutral point commonly connected with the respective phases along the V-phase coil 43-1 connected via the S1 switch 42-1 and the VA node 45, and the voltage reached at the neutral point is divided into a half of it. In the first stage, the half of the voltage is applied to the U-phase coil 43-2 in a direction that the voltage progresses, and the remaining half of the voltage is applied to the W-phase coil 43-3 in a reverse direction that the voltage progresses in the first stage to collide with the voltage progressed by the first stage switching, so that the collision becomes a factor of interrupting the flow of currents. In order to reduce the interruption, switching is made with a dead time upon switching, which prevents only damages to devices but can not prevent a functional resistance of obstructing the generation of a phase difference of the voltage and current and the flow of currents.
Accordingly, this causes a voltage to increase when in a high-speed rotation.
FIG. 4b is a sequence chart for controlling angles and real-time switching of an inverter circuit of an electric motor used in a conventional art, which is shown for explaining a dead time 50.
In the sequence chart, when changing into a U+phase 48 and a U+phase 49, that is, when changing polarities between positive and negative in respective phases, the dead time 50 is required due to collisions with a reverse electromotive force, and it is determined whether driving is stable and devices are destructed by a condition of the required dead time.
Accordingly, an inverter structure of such driving method is a combinational logic switching circuit and has difficulties in series driving, and does not take reactance due to frequency conversions into consideration, only changing a brush-type electric motor into an electronic type in driving.
The present invention has been devised to solve the above problem, so it is an object of the present invention to reduce reactance by controlling to obtain dynamic forces and eletromotive force with alternate magnetic flux induced even though currents flow only in one direction (direct current, in series) by constructing plural coils having different winding directions or more coils in a single, three-phase, and multiple-phase.
It is another object of the present invention to provide a ternary electric power signal by applying voltages to a magnetic circuit with an OR-type combinational logic switching circuit.
It is a further object of the present invention to reduce a magnetic hysteresis loss by ascending and descending a magnetic flux density (B) value with a reference of a non-induction point in a magnetic circuit using a ferromagnetic material.
It is another further object of the present invention to provide a new pole-converting point by direct current (DC) characteristics appearing when switched in order for a positive voltage and a negative voltage to be applied only in one direction to coils wound in different directions by using different magnetic hysteresis curves appearing according to winding directions.
It is a still another further object of the present invention to maximize the efficiency of electric currents with a construction of a phase-series driving circuit.
In order to achieve the above objects, by one characteristic of the present invention, an electromagnetic circuit combining an electric circuit and a magnetic circuit has a switching control unit as a magnetic circuit and an OR-type combinational logic switching control circuit for controlling respective phases in series and direct current, and an alternating magnetic flux induction unit for inducingalternating magnetic flux in an m-waveform type of DC characteristics applied by a manner that switches are alternately turned on and the switches are simultaneously turned on at pole-converting point newly appearing about a non-induction line or non-induction point).
In the switching control unit, one coil of a magnetic circuit is wound clockwise (S direction) and the other coil is wound counterclockwise (Z direction). If a semiconductor switch or a superconductive switch mounted in front of the coil wound clockwise (S direction) is turned on (the semiconductor switch is turned off), the positive voltage of a direct current (DC) voltage source flows to a diode or a device for preventing a reverse bias which is connected to the end of the coil along the S-direction coil and then returns to the negative terminal of the DC voltage source, to thereby induce a magnetic flux of N pole in the magnetic circuit. If the semiconductor switch or the superconductive switch mounted in front of the Z-direction coil is turned on (the other semiconductor switch or the superconductive switch is turned off), the positive voltage of the DC voltage source flows to a diode or a device for preventing a reverse bias which is connected to the end of the coil along the Z-direction coil and then returns to the negative terminal of the DC voltage source, to thereby induce a magnetic flux of S pole. If the semiconductor switches or superconductive switches in front of the S-direction and Z-direction coils are simultaneously turned on, voltages are applied in both directions so that a non-induction occurs in the coils and a neutral zone appears. The same amount of DC current as the input current returns to the negative terminal of the DC voltage source at a common connection node connected with output terminals of the diodes or devices for preventing a reverse bias which are mounted behind the coils.
In the alternating magnetic flux induction unit, the semiconductor switch or superconductive switch connected to the S-direction coil out of the coils wound in reverse to each other is turned on (the semiconductor switch for the Z-direction coil is turned off) to apply a voltage, current increases in the positive direction from a neutral line during the turn-on time by a desired amount, and, after the increase up to the desired amount, is maintained parallel with the time coordinate. At this time, if the semiconductor switches or superconductive switches connected in front of the S-direction and Z-direction coils are all turned on, the current in the S-direction coil drops to a half of it and a half of the current flows in the Z-direction coil so that no induction occurs in a magnetic substance in the coils. At this state, if the semiconductor switch or superconductive switch connected in front of S-direction coil is turned off, the current in the Z-direction coil increases. By repeating the switching as above, voltage-applying curves of the S-direction and Z-direction coils are formed over or below a neutral line of DC characteristics differently from alternate current (AC) waveforms, so that the non-induction point or non-induction line appears about a point of a half of the applied voltage.